The present invention relates to analyzers for the analysis of steel samples and particularly to a crucible loading and unloading mechanism for automatically moving crucibles into and out of an induction furnace of such an analyzer.
In analyzers used, for example, in the steel industry for determining the carbon and/or sulphur content of steel specimens, such as Model No. CS-46 commercially available from Leco Corporation of St. Joseph, Michigan, in the past it has been necessary to manually load the ceramic crucibles into the induction furnace. The induction furnace in turn heats the specimen within the ceramic crucible combusting it at temperatures of about 1700.degree. C. to generate gases representative of the sulphur and/or carbon content of the specimen.
In many laboratories conducting such analysis, a great number of sample analyses are conducted during a day's operation. Once the analysis is completed, the expended crucibles are very hot and tongs are required to handle them. Such manual crucible loading and unloading process is time consuming, tedious, and slow.
It is frequently desirable to do several analyses in a particular sequence to ascertain changes in the carbon and/or sulphur content of a specimen as various steel manufacturing parameters are varied. If a manual loading system is employed, it is possible to mix up the specimen sequence and obtain erroneous results.
Some attempts have been made to provide automatic loading of crucibles into an induction furnace. Such efforts include the sliding of crucibles along a track into the induction station or providing a turntable in which crucibles are rotatably moved into the induction station. The analyzers in which the crucible loading and unloading mechanism is employed are relatively compact and, thus, require a compact crucible handling system. Such prior attempts to provide an automatic crucible handling system have not been usable, however, due in part to the complexity and bulk of their construction and their lack of reliability.